2003 V40 manual 5th gear slipping
 

Hi im from the UK... new here and a new Volvo owner. I recently purchased a 2003 V40 1.6s manual. On driving it today it slipped from 5th gear into neutral. I re-engaged 5th gear and it popped back into neutral. All other gears sound and work OK. I drove home in 4th gear. Any idea of the problem? Is it going to be expensive?

Hope you can help. Thanks in advance.